Evaluation and application of static headspace-multicapillary column-gas chromatography-ion mobility spectrometry for complex sample analysis.

An evaluation of static headspace-multicapillary column-gas chromatography-ion mobility spectrometry (SHS-MCC-GC-IMS) has been undertaken to assess its applicability for the determination of 32 volatile compounds (VCs). The key experimental variables of sample incubation time and temperature have been evaluated alongside the MCC-GC variables of column polarity, syringe temperature, injection temperature, injection volume, column temperature and carrier gas flow rate coupled with the IMS variables of temperature and drift gas flow rate. This evaluation resulted in six sets of experimental variables being required to separate the 32 VCs. The optimum experimental variables for SHS-MCC-GC-IMS, the retention time and drift time operating parameters were determined; to normalise the operating parameters, the relative drift time and normalised reduced ion mobility for each VC were determined. In addition, a full theoretical explanation is provided on the formation of the monomer, dimer and trimer of a VC. The optimum operating condition for each VC calibration data was obtained alongside limit of detection (LOD) and limit of quantitation (LOQ) values. Typical detection limits ranged from 0.1ng bis(methylthio)methane, ethylbutanoate and (E)-2-nonenal to 472ng isovaleric acid with correlation coefficient (R(2)) data ranging from 0.9793 (for the dimer of octanal) through to 0.9990 (for isobutyric acid). Finally, the developed protocols were applied to the analysis of malodour in sock samples. Initial work involved spiking an inert matrix and sock samples with appropriate concentrations of eight VCs. The average recovery from the inert matrix was 101±18% (n=8), while recoveries from the sock samples were lower, that is, 54±30% (n=8) for sock type 1 and 78±24% (n=6) for sock type 2. Finally, SHS-MCC-GC-IMS was applied to sock malodour in a field trial based on 11 volunteers (mixed gender) over a 3-week period. By applying the SHS-MCC-GC-IMS database, four VCs were identified and quantified: ammonia, dimethyl disulphide, dimethyl trisulphide and butyric acid. A link was identified between the presence of high ammonia and dimethyl disulphide concentrations and a high malodour odour grading, that is, ≥ 6. Statistical analysis did not find any correlation between the occurrence of dimethyl disulphide and participant gender

Projection methods in conic optimization

There exist efficient algorithms to project a point onto the intersection of a convex cone and an affine subspace. Those conic projections are in turn the work-horse of a range of algorithms in conic optimization, having a variety of applications in science, finance and engineering. This chapter reviews some of these algorithms, emphasizing the so-called regularization algorithms for linear conic optimization, and applications in polynomial optimization. This is a presentation of the material of several recent research articles; we aim here at clarifying the ideas, presenting them in a general framework, and pointing out important techniques

The Privatization of Metropolitan Jakarta's (Jabodetabek) Urban Fringes:The Early Stages of "Post-Suburbanization" in Indonesia

Problem, research strategy, and findings: Recent metropolitan development in developed countries is associated with post-suburbia, or a decline in population in the former central city and the growth of polycentric structures outside the traditional core. Current urban development in Asian cities, particularly in the Jakarta metropolitan region (Jabodetabek), also reflects an early stage of post-suburbia. We examine physical development patterns and the changing role of public and private sectors, although our approach is descriptive in nature. The rapid growth in fringe areas that have developed from dormitory communities into independent towns, triggered by privatization of industrial estates and multifunction new towns, shows typical post-suburban patterns. The national government's pro-growth economic policies and the local autonomy granted to local governments have given the private sector the power to largely control the acquisition, development, and management of land in fringe areas, accelerating post-suburban development patterns.Takeaway for practice: Planners in developing nations must be alert to the rapidly increasing role of the private sector, recognizing how the private sector can help the government to respond to regional needs for housing, jobs, shopping and educational opportunities, and infrastructure while understanding the key role that planning can and should play in ensuring private sector actions do not exacerbate regional problems and lead to uncoordinated public responses

A test of whether millet acreage in Niger is determined by official or private market prices

Niger has two separate marketing channels for grain: one is the official system operated by the government; the other is a parallel channel of private traders. Researchers or policy-makers wanting to study effects of price policies on producers are faced with two sets of prices. This paper seeks to answer the question, which prices matter? Non-nested hypothesis tests are conducted for millet-acreage response equations. The results show that prices from the larger private market are the prices that matter

A review of applying second-generation wavelets for noise removal from remote sensing data.

The processing of remotely sensed data includes compression, noise reduction, classification, feature extraction, change detection and any improvement associated with the problems at hand. In the literature, wavelet methods have been widely used for analysing remote sensing images and signals. The second-generation of wavelets, which is designed based on a method called the lifting scheme, is almost a new version of wavelets, and its application in the remote sensing field is fresh. Although first-generation wavelets have been proven to offer effective techniques for processing remotely sensed data, second-generation wavelets are more efficient in some respects, as will be discussed later. The aim of this review paper is to examine all existing studies in the literature related to applying second-generation wavelets for denoising remote sensing data. However, to make a better understanding of the application of wavelet-based denoising methods for remote sensing data, some studies that apply first-generation wavelets are also presented. In the part of hyperspectral data, there is a focus on noise removal from vegetation spectrum